190. Synthese einiger 8-substituierter 2-Methyl-1,2,3,4-tetrahydroisochinoline

Article abstract of DOI:10.1002/hlca.19850680704

A general route to 8-substituted tetrahydroisoquinolines is exemplified by preparetion of the 2-methyl-1,2,3,4-tetrahydroisoquinolin-8-ol (11), the -8-carbaldehyde oxime (12) and the -8-carbonitrile (13).It involves the conversion of isoquinoline (1) by partially modified Steps 1,2,3, and 5 (see the Scheme) into the 5-bromo-8-nitro derivative 5, reduction of the latter to the 8-amino derivative 8 and replacement of the NH2-group with an appropriate substituent by a Sandmeyer-like reaction.The selective reductions of the N-containing ring in 6 (Steps 5,6, and 8) and of the NO2-group in 5 (Steps 4 and 7) were also studied.